Mycoplasma hyopneumoniae (M. hyo.) is a bacterial respiratory pathogen that causes Enzootic Pneumonia in pigs. Even though M. hyo. is rapidly inactivated in the environment and by disinfectants, it can survive for quite some time in cool and wet environments.
The organism is generally endemic in swine herds and at that status, the clinical signs are typically mild. Production losses are mostly seen through slowed growth rates. Infection of naïve animals, however, will be characterized by much more severe clinical signs, higher mortality and more significant production losses.
Additionally, the presence of M. hyo. will greatly enhance the negative effects of other respiratory infections like Porcine Reproductive and Respiratory Virus (PRRSV), Swine Influenza Virus (SIV), Actinobacillus pleuropneumoniae (APP), or Pasteurella, resulting in a much more pronounced overall disease severity.
The VDX lab employs two methods to detect the presence of M. hyo. Polymerase chain reaction (PCR) is used to detect the presence of the bacteria in nasal swabs and oral fluid samples. PCR is a fast and accurate method of testing for the presence of pathogens in an individual animal or a pen-based sample. General turnaround time is next day, after the sample has been received in the laboratory.
In the endemic stage, the number of M. hyo. organisms is low or very low, so as an alternative to direct pathogen detection, the ELISA test is available to detect the presence of antibodies to M. hyo antibodies in the serum of individual animals. These antibodies will still be present as part of an ongoing immune response to infection when M. hyo. itself is no longer detectable in the animal. ELISA is an affordable and accurate method of determining if animals have been exposed to the bacteria.
Both the direct pathogen detection by PCR and the antibody detection by ELISA are efficient tools to work towards the goal for high-health herds to eliminate M. hyo. from the herd and, through a surveillance program, monitor for re-introduction.